package com.atguigu.netty.heartbeat;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.timeout.IdleStateHandler;

import java.util.concurrent.TimeUnit;

public class MyServer {

    public static void main(String[] args) throws InterruptedException {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();

        ServerBootstrap serverBootstrap = new ServerBootstrap();

        try{
            serverBootstrap.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .handler(new LoggingHandler(LogLevel.INFO))
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline pipeline = ch.pipeline();
                            /*
                             * 加入netty提供的IdleStateHandler
                             * 说明
                             * 1、IdleStateHandler是netty提供的处理空闲状态的处理器
                             * 2、long readerIdleTime 表示多长时间没有读，就会发送心跳检测包，检测连接状态
                             * 3、long writerIdleTime 表示多长时间没有写，就会发送心跳检测包，检测连接状态
                             * 4、long allIdleTime 表示多长时间没有读写，就会发送心跳检测包，检测连接状态
                             *
                             * 5、文档说明
                             * Triggers an {@link IdleStateEvent} when a {@link Channel} has not performed
                             * read, write, or both operation for a while.
                             * 6、当IdleStatEvent触发后，就会传递给管道的下一个handler去处理，通过调用下一个handlere的userEventTriggered
                             *
                             * IdleStatEvent 读空闲、写空闲、读写空闲
                             */
                            pipeline.addLast(new IdleStateHandler(0, 5, 0, TimeUnit.SECONDS));
                            // 加入一个对空闲检测进一步处理的handler（自定义）
                            pipeline.addLast(new MyServerHandler());
                        }
                    });
            ChannelFuture channelFuture = serverBootstrap.bind(7000).sync();
            channelFuture.channel().closeFuture().sync();
        }finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

}
